Commander Birch was a trifle uneasy when he found there was more than a popple on the sea; it was, in fact, distinctly choppy. Strictly speaking, he ought to have been following up the picket–boat, but he was satisfied that the circumstances were sufficiently urgent for him to take risks.

Anything that is of little importance or worth.

Shakespeare

Trifles light as air / Are to the jealous confirmation strong / As proofs of holy writ.